[Unit]
Description=FirstBoot
After=network.target
Before=rc-local.service
ConditionFileNotEmpty=/root/firstboot.sh

[Service]
ExecStart=/root/firstboot.sh
ExecStartPost=/bin/mv /root/firstboot.sh /root/firstboot.sh.done
Type=oneshot
RemainAfterExit=no

[Install]
WantedBy=multi-user.target